In an information recording medium of a recording type, such as a CD-R (Compact Disc-Recordable), a DVD-R, a DVD-RW, and a DVD+R, for example, as described in patent documents 1 and 2, etc., there is also developed an information recording medium, such as an optical disc, of a multilayer type or dual layer type or multiple layer type, in which a plurality of recording layers are laminated or stacked on the same substrate. Then, on an information recording apparatus, such as a DVD recorder, which performs recording with respect to the dual layer type, i.e., two-layer type optical disc, information is recorded in an irreversible change recording method by heat or the like, or in a rewritable method, into a recording layer located on the front (i.e. on the closer side to an optical pickup) viewed from a laser light irradiation side (hereinafter referred to as an “L0 layer”, as occasion demands), by focusing the laser light for recording on the L0 layer. On the other hand, information is recorded in the irreversible change recording method by heat or the like, or in the rewritable method, into a recording layer located on the rear (i.e. on the farther side to the optical pickup) viewed from the laser light irradiation side (hereinafter referred to as an “L1 layer”, as occasion demands), by focusing the laser light for recording on the L1 layer through the L0 layer.
In the DVD-R DL (Dual Layer) standard, for example, in order to reduce a time length for a finalize process, pre-recording by laser light is performed, in a buffer area, such as a lead-in area and a lead-out area, for example, by a disc manufacturer. Incidentally, in a middle area out of the buffer area, for example, the pre-recording is performed by an information recording/reproducing apparatus, such as a DVD recorder, for example. Thus, even with regard to the DVD-RW DL (Dual Layer) standard, there is also proposed a method which enables the pre-recording by laser light, for example, in the buffer area, such as the lead-in area, the lead-out area, and the middle area, for example.    Patent document 1: Japanese Patent Application Laid Open NO. 2000-311346    Patent document 2: Japanese Patent Application Laid Open NO. 2001-23237